Final answer:
The baker uses 1920 grams of oatmeal in total.
Step-by-step explanation:
To find the total grams of oatmeal the baker uses, we need to multiply the number of batches by the amount of oatmeal per batch. In this case, the baker makes 16 batches of oatmeal bars, and each batch uses 120 grams of oatmeal. So, we multiply 16 by 120 to find the total:
Total grams of oatmeal used = 16 x 120 = 1920 grams
Therefore, the baker uses 1920 grams of oatmeal in total.